1. Technical Field
The present invention relates to bag sealing technology and more particularly, to a packaging bag line-folding and sealing machine, which enhances the sealing yield and prolongs the machine lifespan.
2. Description of the Prior Art
Referring to FIG. 1, a front view of a conventional packaging bag line-folding and sealing machine is illustrated. As illustrated, the packaging bag line-folding and sealing machine 10 comprises an upper sealing unit 11, a lower sealing unit 13, a connection rod 15, two guide units 17, and two line-folding units 19. Moving the upper sealing unit 11 will bias the line-folding unit 19 to fold a packaging bag 12 therebetween the upper sealing unit 11 and the lower sealing unit 13, and then to seal the packaging bag 12.
The upper sealing unit 11 and the lower sealing unit 13 are set facing each other, and movable relative to each other to clamp and seal the packaging bag 12. If the upper sealing unit 11 is moved upwards during actual application, the lower sealing unit 13 will be moved downwards to increase the gap 14 between the upper sealing unit 11 and the lower sealing unit 13 for enabling the packaging bag 12 to be moved through the gap 14 between the upper sealing unit 11 and the lower sealing unit 13.
After the packaging bag 12 has been delivered to a predetermined position, the upper sealing unit 11 will be moved downwards and the lower sealing unit 13 will be moved upwards, causing the upper sealing unit 11 and the lower sealing unit 13 to clamp and heat the packaging bag 12, finishing the packaging bag sealing operation. In order to improve the packaging bag 12 sealing quality, the line-folding units 19 are controlled to make a folding line one side, for example, the opposing side panels of the packaging bag 12 prior to the action of driving the upper sealing unit 11 and the lower sealing unit 13 to seal the packaging bag 12.
The two guide units 17 are coupled to the upper sealing unit 11, each defining therein a groove 171. The line-folding units 19 each have one end thereof respectively coupled to the connection rod 15, and are respectively coupled to the grooves 171 of the guide units 17 by a respective coupling device 191 that is movable along the mating groove 171. When moving the upper sealing unit 11 relative to the connection rod 15, the line-folding units 19 are moved along the grooves 171 of the respective guide units 17, causing the line-folding units 19 to turn about the connection rod 15.
During movement of the upper sealing unit 11 and the lower sealing unit 13 toward the packaging bag 12, the line-folding units 19 will be moved toward the opposing side panels of the packaging bag 12 to compress the packaging bag 12, making a folding line on the packaging bag 12. Thereafter, the upper sealing unit 11 and the lower sealing unit 13 start sealing the packaging bag 12.
The aforesaid prior art packaging bag line-folding and sealing machine 10 can make a folding line on a packaging bag 12 and then seal it, however it is still not satisfactory in function. At first, the line-folding units 19 of the packaging bag line-folding and sealing machine 10 are movable by a swinging action. When driving the line-folding units 19 to make a folding line on the packaging bag 12, the folding line thus made may be not presented in an accurately symmetric condition, affecting the packaging quality of the packaging bag 12. Further, if the size (width and/or height) of the packaging bag 12 is changed, the operator must adjust the relative positions of the upper sealing unit 11, the lower sealing unit 13, the connection rod 15, the guide units 17 and/or the line-folding units 19, enabling the line-folding units 19 to make a folding line on the packaging bag 12. However, because multiple component parts must be adjusted, these component parts will affect one another during adjustment. Thus, this adjustment needs quite a bit of time to finish.